The Intelligent Networks (IN) architecture consists of a Service Switching Point (SSP), which is a switching system that is able to intercept telephone calls, and query a Service Control Point (SCP). The SCP is a system which contains service specific logic, and data which allows it to return instructions to the SSP on how further to treat the intercepted call.
Many IN services include a user interaction phase, which typically consists of an announcement being played to the user, and may then require the user to send digits back to the SSP, in order to indicate the requested service.
From existing IN standards, for example European Telecommunication Standard ETS 300 374-1 (pages 163-165) a system is known in which, when the SCP sends an instruction to the SSP to play an announcement to the end user, an instruction may also be sent to the SSP that, at the end of the user interaction procedure, a report should be sent back from the SSP to the SCP. Similarly, from the same document at pages 166-171, when the user interaction procedure involves the user returning digits to the SSP, the SCP can send an instruction to the SSP, instructing the SSP to report at the end of the user interaction procedure, i.e. at the end of digit collection.
However, these prior art systems have the limitation that the service logic is unable to make decisions based on intermediate events occurring during the interaction procedure.